voltage regulator/rectifier

[Mechambo]

Howdy Folks
I have a 25hp yamaha (25NMH) and was wondering if you can tell me is it possible to fit a voltage reg/rectifier to it? If so what is the part number?
Cheers

[boats.net]

Don't have any information on that model number, not sure if any USA models would match it and have same parts.